This study investigated the possible effect of towed dredges during winter and spring fisheries for oyster and scallop on the potentially sensitive Zostera beds and the quality of Zostera in the following summer. A before and after control impact study (BACI) was established; seagrass plots were sampled for seagrass rhizome using SCUBA in mid-winter.
The razor clam (Ensis siliqua) fishery in the north Irish Sea is distributed in a continuous band of activity from Dundalk Bay in the north to Malahide in the south at depths from 2-15m. Fishing activity has increased significantly since 2013 in response to strong market demand for product. The fishery uses hydraulic dredging to extract razor clams and disturbs sediment to a depth of 25cm.
Over 90% of active fishing vessels in the inshore fleet use pots and nets to target crustaceans. Non-retained by-catch in these fisheries are significant especially in the static net (tangle net and gill net) metier. Commercial and non-commercial finfish are also captured in pots and some of this may be retained for bait.
Vessel position reporting is mandatory for vessels under 12m carrying hydraulic dredges and fishing for razor clams in Irish waters. The number of vessels requiring iVMS increased in 2016 as new razor clam fishing areas were opened and as fishing effort in the north Irish Sea increases.
A number of short studies are required to complement the aquaculture advice provided by the Marine Institute to the Department of Agriculture, Food and the Marine in relation to licencing decisions and mitigation measures.